Small leaks, big bills: finding water where it should not be

Restoration Pros will tell you the expensive water damage they see is almost never the dramatic kind. A pipe that bursts gets found in an hour. The damage that runs to five figures is a supply line that wept under a sink for eighteen months, or a pipe boot on the roof that let a cup of water into the attic every time it rained. Water is patient, and it only needs to be ignored.

Here is where to look, once a season, with a flashlight. The whole tour takes twenty minutes.

Under every sink

Open the cabinet and put your hand on the floor of it. Look at the supply lines, the shutoff valves and the trap. Braided steel supply lines have a life of about ten years and fail without warning; if yours are the gray plastic kind, replace them now. A cabinet floor that is swollen or has a dark ring has been wet.

The toilet

A toilet that runs is wasting water, and one that rocks or has a soft floor around the base has a failed wax ring, which is a slow leak into the subfloor. Put a few drops of food coloring in the tank; if it shows in the bowl without a flush, the flapper is leaking.

Behind the washing machine

The rubber hoses that came with the machine are the single most common cause of a flooded laundry room. Replace them with braided steel every five years, and turn the valves off when you travel. Check the standpipe drains fast enough that the machine does not overflow it.

The water heater

Look under it and at every fitting on top. Read the water heater piece in this section for the rest.

The refrigerator, the dishwasher, the ice maker

Pull the fridge out once a year and look at the ice maker line and the floor. Dishwashers leak at the door gasket and the supply under the sink. A soft or discolored floor in front of either is a leak that has already been going a while.

The attic

After a heavy rain, go up with the flashlight and look at the underside of the roof deck around every pipe, vent, chimney and valley. Dark stains, wet insulation, daylight. A stain that is dry may be old, but a stain that is growing is a roofer's job this month.

Ceilings and walls

A brown ring on a ceiling, paint that bubbles, a baseboard that has pulled from the wall, a musty smell in a closet on an outside wall. Each one is water, and the source is usually above and to the side of where it shows.

The water meter

The one test that catches everything. Turn off every fixture, note the meter reading, wait an hour, read it again. If it moved, something is leaking. Most meters also have a small leak indicator that spins with any flow. If the meter moves with the main house valve closed, the leak is in the service line between the street and the house.

What a leak sensor costs

Battery leak alarms cost less than lunch and go under sinks, behind the washer and beside the water heater. Systems that shut the main valve off automatically when they detect a leak cost a few hundred dollars installed, and some insurers give a discount for them. For a house that sits empty part of the year, they are the difference between a text message and a total loss.

When you find a leak, stop the water first, then call. A plumber fixes the source; if the water has been there long enough to soak drywall or a subfloor, a restoration Pro dries the structure, and the sooner they start, the less has to come out.